Xycom XVME 590 Manual page 54

XVME-500/590 Manual
February, 1988
Gain Factor
of 2
Example 2: Reading and Initiating a Conversion at Channel 15
By writing OFH to the module base + 85H (in the Random Channel mode), the Gain
for channel 15 can be read (the gain is read at bits D6 & D7). When reading
RAM
base + 85H, D5 will always be zero because it is grounded.
conversion is initiated on channel 15 (See Figure 3-4).
Gain
is read here
A/D Data Input Register (Base + word location 86H)
3.3.4
The converter produces digital data which corresponds to the applied analog
A/D
input from a specified channel.
processor at the 16-bit A/D Data Input Register (base + 86H). A word register (16-
b i t ) i s u s e d t o p r o v i d e t h e s p a c e n e c e s s a r y f o r 12-bit resolution.
information in this register may be read in either a byte or word format.
D6
0 1 1
Enables the
Register to
Write* to
Gain RAM
Figure 3-3. Select Channel 8 For Gain
X X 0
1 I
Factor'
Enables
Register for
Convert Mode
Figure 3-4. Conversion at Channel 15
0 1 0
Selects Channel
8 for gain
programming
1
1
0
Selects Channel
15 for a gain
Read /Convert
This digital data is accessible to the 'Host'
3-10
D O
0 0
In addition, a
D O
1 1
Digital